Suspected iatrogenic paradoxical embolization in a cat.

A cat was evaluated for a 5-year history of progressive, episodic, exercise-induced cyanosis and panting. Diagnostic testing demonstrated tetralogy of Fallot with predominant right-to-left shunting and right-sided heart failure. Following diagnostic catheterization, the cat developed clinical signs consistent with systemic arterial thromboembolization and was euthanized. Necropsy findings included multiple thrombi within the right atrium and ventricle, and thromboemboli within the terminal aorta and right common carotid artery, a condition most consistent with iatrogenic paradoxical embolization secondary to diagnostic catheterization. Paradoxical embolization and thromboembolic complications of diagnostic catheterization are discussed.